<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>慕课网菜单的显示与隐藏</title>
		<style>
			span {
				display: inline-block;
			}
			.nav {
				width: 1152px;
				height: 380px;
				background-color: blue;
				margin: 0 auto;
				position: relative;
			}
			.zuo{
				width: 255px;
				height: 380px;
				background-color: #39364d;
				color: white;
				float: left;
			}
			.zhong {
				width: 700px;
				height: 380px;
				background-color: #fff;
				display: block;
				position: absolute;
				top: 0px;
				left: 255px;
			}
			img {
				width: 895px;
				height: 380px;
				float: left;
			}
		</style>
	</head>
	<body>
		<div class="nav">
			<span class="zuo">前端开发</span>
			<span class="zhong">我是要显示与隐藏的菜单</span>
			<img src="1.jpg" alt="">
		</div>
	</body>
</html>